3c2761a6-ec4d-420a-842c-3ccc936813cf 2025-05-15T22:02:57.480562Z ISO 19115-3 - SEXTANT 1.0 Globcurrent Combined (Absolute Geostrophic + Ekman) Surface Current Velocities over Global Ocean on a 6-hourly 0.25° Resolution Grid, version 3 2014-01-01 creation CLS-L4-CUReul_hs-ALT_SUM-v01.0 This dataset contains the version 3 of combined surface current velocities, i.e. absolute geostrophic velocities products from multi-satellite observations over Global Ocean added to Hs depth Ekman velocities computed from ECMWF wind stress with an Ekman model fitted onto drifting buoys[Rio et al. 2014], on a geographical grid with 0.25 degree resolution, from 1993 to 2017. CERSAT Piolle Jean-Francois IFREMER 02 98 22 46 91 02 98 22 45 33 Centre Bretagne - ZI de la Pointe du Diable - CS 10070 - 29280 Plouzané Brest France Jean.Francois.Piolle@ifremer.fr custodian https://sextant.ifremer.fr/geonetwork/srv/api/records/3c2761a6-ec4d-420a-842c-3ccc936813cf/attachments/globcurrent.png CDS-CERSAT Centre de données ODATIS 2023-11-06 publication geonetwork.thesaurus.local.theme.odatis_centre_donnees Variables ODATIS 2023-10-13 publication geonetwork.thesaurus.local.theme.odatis_variables /Données d'observation/satellite Type de jeux de donnée ODATIS 2023-10-13 publication geonetwork.thesaurus.local.theme.type_jeux_donnee Courants ODATIS aggregation parameters and Essential Variable names 2023-11-27 publication geonetwork.thesaurus.external.theme.NVS.OD1 Aucune condition ne s’applique grid utf8 oceans -180 180 -80 80 1993-01-01 2017-05-15 http://cersat.ifremer.fr/data/products/catalogue WWW:LINK CERSAT Catalogue ftp://ftp.ifremer.fr/ifremer/cersat/documentation/gridded/globcurrent/GlobCurrent_D-280_Product_Handbook_L4_combined_mhr.pdf WWW:LINK User manual for GlobCurrent Eulerian (combined geostrophy + Ekman) currents ftp://ftp.ifremer.fr/ifremer/cersat/documentation/gridded/globcurrent/GlobCurrent_D-280_Product_Handbook_L4_ekman_mhr.pdf WWW:LINK User manual for GlobCurrent Ekman currents ftp://ftp.ifremer.fr/ifremer/cersat/documentation/gridded/globcurrent/GlobCurrent_D-280_Product_Handbook_L4_geostrophy_mhr.pdf WWW:LINK User manual for GlobCurrent Absolute Geostrophic currents https://globcurrent.nersc.no/system/files/pubdeliver/GlobCurrent_D-140_TN-1-Year-1_v0.5-signed.pdf WWW:LINK GlobCurrent Analysis and Interpretation Framework https://globcurrent.oceandatalab.com/?date=1429876800000&timespan=1d%3B1w&products=3857_GlobCurrent_L4_geostrophic_streamline%2C3857_GlobCurrent_L4_geostrophic_nrt_vectorfield%2C3857_GlobCurrent_drogue_15m%2C3857_ODYSSEA_SAF_SST%2C3857_ODYSSEA_MED_SST%2C3857_ODYSSEA_NWE_SST%2C3857_ODYSSEA_SST&extent=-18785164.06875%2C-10459031.452861%2C18785164.06875%2C10459031.452861&opacity=100%2C100%2C100%2C100%2C100%2C100%2C100&stackLevel=120%2C120.01%2C140%2C50%2C50.01%2C50.02%2C10 WWW:LINK ESA Globcurrent Portal Ocean Surface Currents (OSC) can be considered as the cumulative results of local and remote factors, including highly variable winds, surface and internal waves, tides, mixed layer depth and buoyancy fluxes. Interacting with larger scale flows, the influence of these random forces on OSC is not trivial. As often observed, this can lead to well ordered and long lived coherent mesoscale structures, with horizontal scales of 30-300 km, and with time scales of 3-30 days. But, local and non-local interactions also induce transient frontal sub-mesoscale structures, developing complicated patterns with eddies, filaments and shear currents with horizontal scales of 1-10 km, vertical scales of 50-200 m, and ephemeral time scales of 1-3 days. Although surface currents in the ocean are not the simple addition of different current components, in this first version of GlobCurrent products the combined currents are intended as the sum (referred to as total current) of the geostrophic and the Ekman components at the surface. Another product provides similar combined currents at 15m depth. The geostrophic and ekman components are available independently in two other different GlobCurrent products. 25 years of data are available, spanning the period from the beginning of 1993 to the end of 2017, on a 1/25° resolution grid and with a 3-hourly temporal resolution. More details on the calculation of the single components of this combined current can be found in the GlobCurrent Algorithm Theoretical Baseline Document, in the geostrophic currents handbooks and in the Ekman currents handbook. In particular, it should be noted that despite the high temporal (3-hourly) and spatial (1/25°) resolution of the GlobCurrent products grids, by construction, the effective resolution of the geostrophic and Ekman currents is of the order of 5-10 days / 50-100 km. These resolutions will be improved in the future versions of the GlobCurrent products. In addition, due to the reduced accuracy of altimeter measurements in coastal areas, users should be aware that some geostrophic velocities in very local areas close to the coast may be erroneous. These velocities will be flagged in the future versions of the GlobCurrent products.